The manufacture of printer's ink generally involves its placement in a cylindrical metal tub. After each use, the tub must undergo a thorough cleaning to remove the ink that invariably adheres to its interior surface; any remaining material will contaminate future batches of ink placed inside the tub.
Cleaning residual material from a container that had found use in storing or transporting the material permits the reuse of that container. U.S. Pat. No. 40,797 to W. Robinson discloses an apparatus which tumbles a cask about an axis or end over end or in both of these modes. A scouring medium such as a chain, gravel and water, or other material, sealed inside the cask, effectuates its cleaning.
Other devices undertaking the cleaning of containers' insides in a similar manner as the above patent appear in U.S. Pat. Nos. 1,462,917 to J. H. Miller; 1,546,081 to W. H. Jones; 1,594,516 to H. J. Derosha; 1,755,763 to J. T. Barber; and 1,913,979 to C. C. Farrington. These pieces of equipment generally entail tightly sealing a cleaning medium inside the unclean container and clamping the container to the disclosed apparatus. Completing the cleaning procedure then requires the equally cumbersome reverse procedure of releasing the container from the apparatus, unsealing the container, and removing the cleaning medium.
None of these devices permit the cleaning of a container which does not have a completely enclosed interior volume. Nor do any clean the exterior of the containers which would likely have a coating of residual material. Further, none permit the replacement of spent or contaminated cleaning medium within the containers during the cleaning operation.
Cleaning residual material from containers represents a particular problem for tubs used in the manufacturing of printer's inks. The very nature of the inks themselves prohibits their facile removal from the tubs' surfaces. A commonly used procedure involves the use of a caustic heated to about 180.degree. F. Manually scrubbing the tub with the heated caustic represents a difficult and dangerous procedure.
One automated machine employed for cleaning ink tubs makes use of the hot caustic. Accordingly, it requires a source of 220 volt electricity to provide the energy necessary to heat the solvent. It also has permanent plumbing connections to a source of water and to a drain. This expensive equipment occupies a large amount of space where located and consumes a similar quantity of energy to accomplish its task.
As a result, the search continues for equipment and a method that will efficiently and thoroughly clean residual material from the interior as well as exterior surfaces of a container. They should effectuate the cleaning without the necessity of sealing the cleaning medium inside the container or clamping the container to the apparatus.